Electric switch



Jan. 12, 1937. H, M. RocKwELl. 2,067,681

ELECTRIC SW1-,TCH

Filed NOV, l5, 1952 2 sheets-sneet'l Jan. 12, 19371. H. M. RocKWELL 2,067,681

ELECTRIC SWITCH Filed Nov. l5, 1952 2 Sheets-Sheet 2 |mmxmmmmm --69 l NN L11 o brake rod.

Patented .la i. i2, 193? ELECTRE@ SWTCH liingh M. Rockwell, Freeport, N. Y.

'I November l5, i932, Serial No. @42,7%

d Claims.

This invention relates to improvements in ciruit making and breaking devices, and has par ticular reference to such devices of the push and pull type, that is switches having members le o relative longitudinal movement.

.an important object of the invention is to provide a switch of the above mentioned character which will be extremely simple in construction, and with ch currentmconducting wires may be quickly and .sily connected.

Another bject is to provide such a switch in which the wire connecting means constitute switch contacts for engagement by one or more Contact members of the other relatively movable part.

Another object is to provide such a switch which will be particularly well adapted for use in stopf light circuits of vehicles in which the switch is automatically actuated as the brakes of the vehicle are applied and released.

Another object is to provide such a switch which will form a part of the operative connection between the brake pedal and the brakes of a Vehicle.

Another object is to provide such a switch which can be very easily and quickly applied to any commercial vehicle with a minimum .amount of labor.

Such stopI light switches as have been in use prior to this invention have comprised a main body portion rigidly mounted upon the vehicle frame or floor board, and a movable contact member associated with said body portion and connected either to the brake pedal or to the There are many speciiically dinerent kinds or switches commercially available7 but due to diierences of design of different makes of vehicles, these various switches are not interchangeable. The original installations and replacements of such switches have therefore involved considerable labor, and in these arrangements in which the movable member is connected to the brake rod by means of a clamp, such operative connections have sometimes become loose. Another objection has arisen from the employment of one or more strong springs in the switch for returning the movable member to its normal opened position, this adding considerable resistance to the movement of the pedal or the like in applying the brakes. These objectionable features of the prior art devices are overcome by the present invention, which provides a simplified form of stop light switch which can be economically manufactured, and which will (Cl. 200m-59) be thoroughly dependable, strong and durable service.

With the foregoing and other objects, features, and advantages in view, the invention resides in the novel features of construction, combinations, and arrangement of parts hereinafter set forth, shown by way of illustration in the'accompanyintr drawings, and specifically pointed out in the appended claims.

in the drawings,

Figure l is a side elevation of one form of switch embodying the invention and shown diagrammatically as applied to the braking system of a vehicle;

Fig. 2 is a vertical longitudinal sectional view through the switch per se, on an enlarged scale, and Showing the parts in their normal position;

Fig. 3 is a similar view with the parts in their circuit closing position;

Fig. 4 is a detail perspective View of the movable contact member;

Fig. 5 is a vertical transverse sectional view on line 5 5 of Fig. 3;

Fig. 6 is a horizontal sectional view on line 5-6 of Fig. 2

Fig. 7 is a vertical longitudinal sectional view through another form of switch embodying the invention;

Fig. 8 is a horizontal sectional View through the modified form of switch shown in Fig. 7;

Fig. 9 is a fragmentary view similar to Fig. 7, but show the parts in circuit-closing relation;

Fig. lf) is a vertical transverse sectional view taken on line l--lil of Fig. 9; and

Fig. il is a vertical transverse sectional view taken on line ll--li of Fig. 9.

in Fig. l, one form of improved switch l0, embodying the invention, has been shown in association with conventional portions of an automobile braking system, wherein a brake pedal ll is pivoted at i2 and connected by means of brake rods or links i3 to the levers Hi of the brakes I5, only one of which has been illustrated. As the pedal il is depressed, the brake rods are drawn forwardly to actuate the brake which may be of any ordinary or preferred type. The switch lll is interposed between the foot pedal ll, and the brake E5 in such a manner as to constitute a part of the operative connection, and said switch is adapted to transmit the braking pressure.

Referring more particularly to Figs. 2 to 6 inclusive it will be seen that the switch lo includes a main body portion i6 and a (zo-operative member il, which are movable together, and with reference to each other, their relative movement being limited. The main body portion I6 comprises a substantially cylindrical socket i8, havn ing a forwardly extending yoke I9 suitably apertured at 20 for the reception of a clevis pin 2i, or the like, by means of which it may be connected to the pedal II. The socket portion IB is iurther characterized by a recess 22, which extends inwardly from the rear surface thereof, and which is screw threaded as at 23 for the reception of a threaded portion 24 of an insulation block 25. Said block 25 may be formed of any suitable dielectric material, for example fabric-base bakelite, hard rubber, or fibre, and is provided with a substantially central longitudinal bore 2l?, within which is slidable a sleeve 2l of the co operating member Il. The sleeve 2'I is also formed of dielectric material, and is preferably in the nature of a bushing, whose inner periphery is secured, in any suitable manner, to a metallic sleeve 28 which, in turn, is provided at its inner or forward end with an enlarged circular head portion 29. The head portion 29 is capable of longitudinal or axial movement within the recess 22, and is limited by abutment with the bottom of said recess in one direction, and with the inner end of the threaded member 24 in the other direction. The sleeve 28 is internally threaded as at 30 for connection with the forward end of the brake rod I3, and may be securely locked in relation therewith by means of a lock washer 3| and lock nut 32. While the major portion of the sleeve 28 is preferably cylindrical, its outer or rearward end may be milled off or otherwise formed with a hexagonal or square cross section to accommodate a wrench, whereby adjustment can be made relative to the rod I3, and said end extends outwardly beyond the rearward end oi the insulation member 25.

A pair of spaced contact members 33 and 33a are fixed in the dielectric block 25, and preferably disposed at the opposite sides of the bore 2li, and said bore is provided with a groove 34 at a suitable point in its length, in which portions of said contact members 33 and 33a are exposed. The contact members 33 and 33d are preferably in the form of cylindrical extensions of screws 35 and 35a respectively which are seated within suitable screw-threaded sockets 33, and preferably disposed below the surface of the dielectric material as best shown in Figs. 5 and 6. The inner ends of said contact members are prefer ably pointed as at 3`I, and adapted to extend into longitudinally extending holes 35 and 38a, in which ends of the current-conducting' wires 39 and 4D respectively are adapted to be receivcd. The pointed ends 3l of the members are adapted to pierce the insulation of the conducting Wires and thereby form electrical contact with the metal, at the same time expanding the wire against the walls of the holes 33 and 38a, and said connections are entirely concealed Within the dielectric block 25. Extending inwardly from the front surface of the block 25 are a plurality of recesses 4I, within each of which is disposed a compression spring 42, there being six such recesses and springs illustrated in the drawings. The normal arrangement of the p rts is shown in Fig. 2, from which it will be evi nt that the forward ends of the springs 42 bear against the rearward sides of the head member 29 in such a manner as to move said head rnemn ber into abutting relation with the bottom of the recess 22 in the socket member I8.

The dielectric sleeve 21 is provided with a peripheral groove 43 within which is disposed a resilient contact member 44 which, as has been shown in Fig. 4, is in the nature of a metallic ring which normally tends to expand. When the part-s are in their normal positions, as shown in Fig. 2, the Contact connecting ring 44 is disposed in a different plane from the common plane of said contacts 33 and 33a, and the circuit is broken. When, however, the pedal II is de pressed to actuate the brake the main body portion I5 of the switch is moved longitudinally with reference to the co-operating portion I'I, with the result that the ring 44 engages those portions of the contacts 33 and 33a which are exposed in the groove 34, and closes the circuit therethrough. Only a slight amount of movement is necessary to accomplish the making and breaking of the circuit, and by forming the bore 26 with the groove 34 ample provision is made for manufacturing variations both in the diameters and in the distances between the contacts 33 and 33a. If desired, the side walls of said groove 34 may be inclined to fascilitate passage of the ring 44 in disassembling the parts.

When in use for controlling a vehicle stop light the switch Iii is mounted as previously described in connection with Fig. l, the yoke portion 20 being attached in a suitable manner to the pedal Il, and the sleeve 2S being secured to the forward end of one of the brake rods or links I3, thus forming an integral part of the operative connection between the pedal and thc brake. 'Ihe 'wire 39 is inserted in the hole 3B, whereupon the screw Sii may be tightened to force the pointed end 3l of the upper Contact member 33 into electrical engagement with said wire 39. The opposite end of the wire 39 is connected to the stop light 46 mounted at the rear of the vehicle, said stop light being also connected to ground at 4l. The current-conducting wire 40 is similarly connected to the lower contact member 33a, and the rear end is connected to a storage battery 48, or other suitable source of current supply, which is also connected to ground at 49. As the pedal II is depressed to actuate brake, the main body portion IG and co-operating portion I? are first moved with relation to each other against the action o1 the compression springs 42 until the forward end of the insulation block 25 abuts against the rear surface of the head member 29. In this condition the expanding ring 44 has been moved into the common plane of the spaced contacts 33 and 33a and in such a manner as to mutually engage the same and close the circuit, and thereafter continued movement of the brake pedal II in the same direction will cause the entire switch I0 to be moved as a unit and to transmit the full braking force from the pedal to the brake link. When the foot pressure is released from the pedal I I the parts return to their normal positions, in which the brakes I5 are released and the springs 42 cause the circuit through the stop light to be again broken within the switch. It will be evident from this that during the early part of the movement of the pedal I I in applying the brakes only a slight foot pressure required to compress the springs 42, and that after the limit of relative movement has been reached said springs become ineffective and do not add resistance to the braking pressure after circuit has been closed.

Aside from the simplicity of the electrical connections in the switch of this invention, a particularly desirable feature resides in the fact that the same may be Very readily applied to any cornmercial vehicle without necessitating the drilling of holes or other labor operations which have been necessary in connection with the prior art stop light switches. The proportions of the parts are such that the switch is interchangeable with a standard brake-rod yoke, and in order to apply the same it is only necessary to disconnect the brake-rod and substitute'the switch I0 in place of it.

While switch Il) has been shown on the drawings as directly connected to the pedal II, it is toy be understood that this specified location is not necessary, since it may be employed with equal advantage in other locations between the pedal and the brake. Furthermore, the structural details of the switch may be modified in various ways to accommodate it to different installations as will be obvious.

In Figs. 7 to 11 inclusive, one of the numerous possible modiiications has been shown by way of example. By referring to these views in detail, it will be seen that the switch therein shown comprises a block of suitable dielectric material of substantially rectangular cross-section, and provided with a pair of spaced contact members 6I and 62. This block I5!! is formed with a substantially cylindrical cavity or bore 63, and is partly embraced by and clampingly held in the U- shaped body 64 of a steel strap or yoke, the ends 65 of which are apertured like the yoke I9 for reception of the clevis pin 2| whereby it may be mounted in the brake system of a vehicle just the same as the first described embodiment. A metallic sleeve 66 is iitted for limited sliding movement within the cavity 63 said sleeve being internally bored and screw-threaded for attachment to the brake rod I3. Movement of the sleeve is limited in one direction by shoulder portions 6'! engaging against the inner surface of the yoke body 64, and in the opposite direction by a nut 68 which is screwed on the rod I3 and against the outer end of the sleeve 66. Rotation of the sleeve within the block 60 is prevented by key portions 69 outwardly or rearwardly of the shoulder portion 6l.

At an appropriate point in its length, the sleeve 66 is circumferentially grooved and fitted with a dielectric collar or bushing 1I) which is, itself, 1grooved at 1I for reception of the resilient contact connector ring 'I2 substantially like the member 44. Rearwardly of the groove 1I is a longer but shallower groove 13 which provides clearance for those portions of the Contact members 6I and 62 which extend partly into the cavity 63. Normally the contact connector ring 12 is entirely out of the plane of the members 6I and 62 and out of contact with them by reason of the pressure of springs I4 disposed in recesses 'I5 in the end of the sleeve 66. However, when the pedal I I is depressed to apply the brakes of the vehicle, the yoke 64 is moved against the shoulder portions 61 of the metallic sleeve 66, and as a result, the members 6I are moved into engagement with the contact connector ring 12 closing the circuit. After this initial movement, the breaking force, is transmitted to the rod I3 through the metal members 64 and 66 without imposing any undue strain on the circuit-making and breaking means or their insulating members. It is to be noted that the parts are so arranged that as the circuit is made or broken there will be a slight wiping action between the contact members and the resilient contact-connecting ring, and this insures clean surfaces which render the switch at all times dependable in closing the circuit.

As in the first described embodiment, the contact members 6I and 62 may be pointed at one end to pierce the respective wires 39 and 40, or if desired, they may be provided with other means for receiving or attaching the wires by standard clips or otherwise. In some respects the structure shown in Figs. 7 to 11 inclusive is more preferable than that shown in Figs. 2 to 6 because of its greater strength and economy in manufacture. Nevertheless, it will readily be appreciated that both of these forms embody the same principles of operation and relate to the same generic invention.

The first-described form of the invention was disclosed in my allowed application Serial No. 200,995 of which the present application is a continuation in part and a carrying forward. Obviously the invention is susceptible of further modication in the details of construction, combinations, and arrangement of parts, and the right is herein reserved to make such changes as fall within the scope of the appended claims without departing from the spirit of the invention.

Having thus described my invention, what I claim iszl. In a stop light switch for vehicles, a pair of relatively movable co xial members formed of dielectric material, a pair of spaced contact members screwed in one of said dielectric members at opposite sides of its axis, a resilient contact connecting member carried by the other dielectric member and being adapted to alternately make and break the circuit between said spaced contact members, and mounting means for securing the same in a brake link system wherein the switch will iioat as a unit and transmit braking forces.

2. In a stop light switch for vehicles, a pair of relatively movable members formed of dielectric material, a pair of spaced contact members carried by one of said dielectric members, a resilient contact connecting member carried by the other dielectric member and being adapted to alternately make and break the circuit between said spaced contact members, and means associated with each of said dielectric members whereby to mount the same directly in a brake link system, said contact members comprising transversely extending studs, and having their inner ends pointed whereby tol be capable of piercing the insulation of current-conducting wires to form electrical contact therewith.

3. In a stop light switch for vehicles, a pair oi' relatively movable members formed of dielectric material, a pair of spaced contact members screwed in one of said dielectric members, a resilient contact connecting member carried by the other dielectric member and being adapted tol alternately make and break the circuit between said spaced contact members, and means associated with each of said dielectric members whereby to mount the same in a brake link system, said contact members comprising transversely extending studs, and having their inner ends pointed whereby to be capable of piercing the insulation of current-conducting Wires to form electrical contact therewith, the inner ends of said studs and the connected portions of said wires being entirely within the coniines of the dielectric material.

4. In a stop light switch for vehicles, a pair of relatively movable members formed of dielectric material, a pair of spaced contact members screwed in one of said dielectric members, a resilient contact connecting member carried by the other dielectric member and being adapted to alternately make and break the circuit between said spaced contact members, and mounting means associated with each of said dielectric members, said contact members comprising transversely extending studs, and having their inner ends pointed whereby to be capable of piercing the insulation of current-conducting wires to form electrical contact therewith, and said contact connecting members comprising an expansible metal ring disposed in a plane substantially parallel to the common plane of said spaced contact members.

5. In an electric switch, a main body portion, a co-operatlng member having limited sliding movement with reference thereto, a pair of switch contacts mounted in said body portion, said contacts being separated and insulated from each other, and resilient contact connecting means carried by the co-operating member and adapted to be moved into and out of engagement with said spaced contacts, said switch contacts having piercing means for making electrical connection with a current-conducting wire, said resilient contact connecting means comprising an expansion ring.

6. In an electric switch, a main body portion formed of dielectric material and provided with a substantially central bore, a coi-operating member slidable axially in said bore, a pair of cylindrical switch contacts extending transversely in the main body and having exposed portions in said bore, and an expansible ring carried by said co-operating member and adapted to be moved into and out of the common plane of said switch contacts and to mutually engage the same to make and break the circuit.

7. In an electric switch, a main body portion formed of dielectric material and provided with a substantially central bore, a co-opcrating member slidable axially in said bore, a pair of cylindrical switch contacts extending transversely in the main body and having' exposed portions in said bore, the inner ends of said switch contacts being pointed and adapted to pierce confined current-conducting wires to make electrical connection therewith, and a resilient expansible ring carried by said co-operating member and adapted to be moved into and out of the common plane of said switch contacts and to mutually engage the same to make and break the circuit.

8. A stop light switch of the class described, comprising a body of dielectric material having a substantially central longitudinal bore, a substantially U-shaped metallic strap carrying and partly surrounding said body and adapted for connection in a brake link system, a pair of spaced contact members located in the body and having portions exposed in the central bore, means for connecting said contact members with current conducting wires, a cooperating member having sliding movement within the bore, and also adapted for connection in a brake link system, an insulated contact member carried by said cooperating member and adapted aiternately Yto engage and disengage the contact members to make and break the circuit, and means for limiting the sliding movement of the cooperating member within the bere when the contacts are in engagement, and for transmitting full braking forces through the brake link system.

HUGH M. ROCKWELL. 

